Control system for dual rotor pump drives



Dec. 17, 1957 D. J. BLOOMBERG- I 2,815,417

CONTROL SYSTEM FOR DUAL ROTOR PUMP DRIVES Filed Aug. 15 1952 OXIDIZER I Z5 If g u g /7 Z9 3/&

Inventor-g 'David J. Bloovnbevg, by TM 6. W His Attorney.

United States CONTROL SYSTEM FOR DUAL ROTOR PUMP DRIVES David J. Bloomherg, Newton, Mass, assignor to General Electric Company, a corporation of New York Application August 13, 1952, Serial No. 304,141

Claims. (Cl. 60-35.6)

The present invention relates to a gas turbine arrangement and specifically to a control system for a dual rotor pump drive for use in jet propulsion units but is not necessarily limited thereto.

' Mechanically independent dual turbopump combinations tied together by a control system are of the highest import in reaction propulsion units utilizing fluid bipropellant components, where a definite requirement may exist that one of the fluid components must be delivered into the main reaction combustion chamber before the other. Such is accomplished by maintaining a definite pressure relationship between the two fluid flows from the separate pump combinations.

An object of the present invention is to obtain an im proved control system for a dual rotor pump drive.

Another object of invention is the provision of a more flexible and lighter Weight structure for independent control of the drive units of a dual pump combination.

Still another object of the invention is to obtain individual speed controls for the turbine rotors used in a dual pump combination by governing the supply of motive fluid thereto.

A further object of my invention is to obtain better fuel economy in a dual pump combination by using separate pump pressure controls and by eliminating throttling of excess pump pressures in main supply lines.

Still another object of invention is the provision of dual tier bladed turbine rotors with independent mechanical drives for pumping to permit independent power input or speed control for each pump combination.

These and other objects of invention will become apparent from the following description taken in connection with the accompanying drawing which discloses diagrammatically a dual turbopump combination embodying my invention.

In accordance with the illustration of my invention, I employ pressure regulators to control the amount of fuel furnished the sources of motive fluid for the turbine rotors.

Referring now to the drawing, a dual turbopump combination with my improved turbine control is indicated generally at 10 and comprises a pair of mechanically independent, contra-rotating turbine rotors 11, 12, which are connected by drive shafts 13, 14 to pumps 15, 16. The turbopump drive employs double tier blading and partial arc admission in the turbine rotors of the type disclosed in my patent application, Serial No. 193,181, filed October 31,1950, now Patent 2,624,173, having the same assignee. Motive fluid, under elevated temperature and pressure conditions, is supplied to inlets 17, 18, from separate sources of supply, such as combustors 19, 20, respectively, although any gas generation apparatus can be'used as a source of supply of motive fluid. The motive fluid is expanded to a high velocity by conventional inlet structure and directed at the desired angle with respect to turbine rotors 11, 12. The double tier blading is designed so that approximately 75% of the energyavailable in the motive fluid supplied to the tur- 2,816,417 Patented Dec. 17, 19 57 bine rotors is converted in the outer rows of buckets and the remainder of approximately 25% is converted in the inner rows of buckets of the respective rotors.

As in the disclosure of the previously cited patent, intermediate arcuate passage portions 21, 22 displaced angularly from each other by 180 and parallel to the approximately semi-circular arcuate openings for the partial arc admission of the motive fluid, are provided for transferring the flow of motive fluid to and from the respective flow paths in rotor 12, from and to the respective flow paths in rotor 11. These arcuate passage portions 21, 22, are carried by an intermediate structural member (not disclosed here) which is supported in a conventional manner. Normal turbine exhaust passages discharging directly to the atmosphere are indicated respectively at 23, 24. I

With two independent flow paths provided through the turbine portions of the pump combination and with two different sources of supply of motive fluid provided for the turbines, viz. combustors 19, Zll, each tiered rotor can produce a different power output determined by the discharge pressures of the pumps. This is particularly desirable in the case of a system adapted for use in a reaction propulsion motor Where a definite requirement may exist that either the oxidizer or the fuel bipropellant component be delivered first, into the main combustion chamber; depending upon such a precedence requirement, pumps 15, 16 are connected properly to the respective sources of supply, here indicated as oxidizer and fuel.

Check valves 25, 26, arranged to open at predetermined pressures, are provided at the discharge of the respective oxidizer and fuel pumps, leading to the main combustion chamber 40.

Between each outlet of pumps 15, 16, and the check valves 25, 26, are located bleeder lines 27, 28 and 28' and pressure signal lines 29, 29 and 3G, bleeder line 27 leading directly to the combustors 19 and 20, while bleeder line 28 and signal line 29 are connected to combustor 19 through pressure controlled regulator 31 and line 31a, and bleeder line 28 and signal lines 23 and 30 are connected to combustor 20 through differential pressure regulator 32 and line 32a.

In the operation of the oxidizer and fuel pumps, which are independently connected to the separate rotors, the power converted from the motive fluid supplied from the first combustor is sufficient to drive the first rotor and its pump at a speed great enough to develop pressure to open the check valve and start delivery of the first pumped fluid. The remaining (approximately 25%) of the available energy of the motive fluid supplied causes the second rotor and its pump to rotate but at a speed insuflicient to enable the second pump to develop enough pressure to open its check valve. After motive fluid from the second combustor is supplied to the second rotor, approximately of the energy available therein is converted in the outer row of buckets of this rotor which will enable the second pump to develop enough pressure to open its check valve and start delivery of the second pumped fluid, the remainder of the energy in the motive fluid supplied from the second combustor being converted in the inner row of buckets of the first rotor.

For the purpose of illustration, the first or control fluid pump, in this instance 15, is started by initiating the operation of combustor 19 which supplies motive fluid to the first rotor 11, usually by means of a starter, such as indicated diagrammatically at 33. This starter is a gas generating device and may be a small size combustor, operating similarly to the combustors 19 and 20 and providing sufficient motive fluid for the initial operation of the oxidizer and fuel pumps, which, when brought up amour to operating speed, furnish the bipropellant components to the combustors initially (by which time the starter has completed its function) and later to the main combustion chamber. Check valve 25 at the discharge of this pump holds bac' the flow of oxidizer to the main combustion chamber 49 until a minimum predetermined delivery pressure is attained although as soon as the first fluid pump 15 is started, oxidizer is furnished to the combustor 19, its admission being controlled by appropriate valve means (not shown). As the pump pressure builds up, it is transmitted respectively by signal lines 29 and 29' to the regulators 31, 32, which control the admissionof the fuel through the bleeder lines 28 and 23 into the combustors 15 and 20.

The flow of fuel into combustor 19, being controlled by the pressure controlled regulator 31, determines the speed of the control rotor 11 and so determines the discharge pressure of fluid pump 15. The diflerential pressure regulator 32 subjected to the pump pressures of both fluid pumps by way of signal lines 29' and 30 will control the fuel flow into the second combustor 2t? and thereby control the supply of motive fluid available from combustor 2., so determining the rotational speed of rotor 12 and the discharge pressure of pump 16.

It is evident that the turbopump combinations, though mechanically independent of each other, are tied together by means of the control arrangement described above, in a manner to prevent a second fluid from getting into the main combustion chamber ahead of the first fluid at any time during starting operation or failure of the fuel flow system.

The proportioning of the tier blading to give the arbitrary division of power conversion in the ratio of '75%25% is taken merely as an example, since the speed that the rotors attain Will determine the division of the power conversion ratio, which may vary from 60%40% to 80%-20%.

While a particular embodiment of my invention has been illustrated and described, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the spirit of the invention, but it is intended to cover all such changes and modifications as come within the scope of the appended claims.

What i claim. as new and desire to secure by Letters Patent of the United States is:

l. in a control system for a gas turbine arrangement comprising a dual pump drive, a pair of tier bladed turbine rotors, separate means for supplying motive fluid to part of the arc of one tier of blading on each rotor, flow directing means between said pair of tier bladed turbine rotors for directing said motive fluid in series flow relationship between corresponding opposing outer and inner tiers of said rotors, separate pumping means connocted in driven relation to each of said tier bladed turbine rotors, and connected to the discharges of said pumping means and responsive to pressures generated by said pumping means for governing the operation of said first-mentioned means to control the supply of motive fluid to the rotors.

2. in a system as set forth in claim 1, the pressure responsive means including valve means which are opened in a predetermined relationship so that one of said separate pumping means develops delivery pressure prior to the other.

3. In a dual pump drive system comprising first and second mechanically separate turbopumps arranged to deliver first and second fluids respectively to a common point. first and second means for supplying motive fluids to the rotors of said first and second turbopumps respectively, said motive fluid resulting from a iii-propellant component reaction involving a fuel, means to effect the introduction of fuel to said first motive fluid supply means in response to pump fluid pressure from said first turbopump, and means responsive to the difference in pump fluid pressure from said first and second pumps to control the supply of fuel to said second motive fluid supply means.

4. In a gas turbine arrangement for a dual pump drive comprising first and second pump, a pair of mechanically independent rotors connected respectively to each of said pumps, first and second separate sources of motive fluid for first and second rotors respectively said motive fluid being the reaction product of bi-propellant components one of which is a fuel, means responsive to pressure in said first pump for controlling the fuel provided to said first source of motive fluid, differential pressure responsive means arranged to sense the fluid pressures at the discharges of said pumps and control the fuel provided to said second source of motive fluid for governing the supply of fuel from said second pump.

5. A control system for a combustion chamber comprising a pair of mechanically separate turbopump arrangements for supplying said combustion chamber with fluid bi-propellant components including a fuel, each of said arrangements comprising a rotor connected to a pumping means and a source of motive fluid for driving said rotors, said motive fluid comprising the product of the reaction between said fluid bi-propellant components, each of said pumping means being connected to respective sources of bi-propellant components and the sources of motive fluid and having a check valve at their discharge, means for initiating the operation of the first of said pair of turbopump arrangements, pressure responsive means connected to the discharge of the pumping means of said first turbopump arrangement to control the flow of fuel into its source of motive fluid and pressure differential responsive means connected to the discharges of both pumping means to control the introduction of fuel to the source of motive fluid for the second turbopump arrangement.

6. in a jet propulsion device having a main combustion chamber wherein the reaction of first and secondfluid bipropellant components occurs, first and second pumping means individually connected thereto and to separate sources of said first and second components respectively for providing said chamber therewith, first and second tier-bladed rotors connected to said first and second pumping means respectively and designed to convert in the outer rows thereof a major portion of the available energy of the motive fluid provided thereto, said motive fluid comprising the product resulting from the reaction of said.

fluid oi-propellant components, means for directing said motive fluid from the outer rows of the tier-bladed rotors into corresponding opposite inner rows of the tier-bladed rotors wherein the remainder of the available energy in the motive fluid is converted, means for receiving the exhaust from said inner rows of said rotors, first and second sources of motive fluid for each of said first and second rotors respectively comprising combustors to which fluid bi-propellant components are supplied from the discharges of said pumping means, valve means opening at predetermined pressures located at the discharges of said pumps leading to said main combustion chamber, and means for controlling the delivery of fuel into said sources of rotor motive fluid.

7. in a device as set forth in claim 6, said means for controlling the delivery of fuel into said sources of rotor motive fluid comprising a pressure controlled regulator for governing the delivery of fuel into said first source of motive fluid, said pressure controlled regulator being connected to the discharge of said first pumping means and operable to control said delivery in accordance with the pressure of said first pumped fluid bi-propellant components, and a diiferential pressure regulator for selective fuel delivery into the second of said sources of motive fluid including means for establishing a resultant pressure from the discharges of said pumps to determine said delivery.

8. In a device as set forth in claim 7, said first source of motive fluid including means for initiating the operation thereof and start of pumping action.

9. A combination of elements for controlling the flow of fluid bi-propellant components into the main combustion chamber of a reaction propulsion unit supplied by a pair of turbine rotor driven pumps furnishing respective components each including pressure responsive valve means allowing a fluid bi-propellant component to flow when a preselected pressure is exceeded and to prevent such flow when the pressure drops, combustor means for supplying a motive fluid to each of a pair of rotors said combustor means being furnished bi-propellant components from the discharges of said pumps, said motive fluid comprising the product of the reaction between said fluid bi-propellant components, and means for regulating the flow of one of said fluid bi-propellant components into said means for supplying motive fluid to control the starting sequence of said rotors, said last-named means comprising means responsive to the discharge pressure of the pump to be started first for controlling the supply of motive fluid to its turbine rotor and means responsive to the difference in the discharge pressure of both pumps to control the supply of motive fluid to the rotor to be started second.

10. A system for controlling the flow of fluid bi-propellant components one of which is a fuel, into a combustion chamber comprising a pair of turbopump units mechanically independent of each other and connected to respective sources of supply of said components, each of said units having a tier-bladed rotor and a source of motive fluid for operation thereof said motive fluid comprising the product of the reaction between said fluid bipropellant components, said rotors being designed so that substantially the larger portion of the energy used in the system is converted in the outer tiers thereof, means for conveying motive fluid from each of the outer tiers of said rotors to the inner tiers of the other of said rotors, means for exhausting said motive fluid from the inner tiers of said rotors, regulating means for governing the delivery of fuel into said sources of motive fluid, means for initiating the operation of that of said turbopump units which is to deliver fluid first, and means for delaying delivery of said fluid bi-propellant components to said main combustion chamber comprising means responsive to the pump discharge pressure of the turbopump unit to be started first for controlling the supply of motive fluid to its tierbladed rotor and means responsive to the difierence in the fluid discharge pressure of the two pumps to control the supply of motive fluid to the remaining tiered rotor.

References Cited in the file of this patent UNITED STATES PATENTS 1,052,588 Janicki Feb. 11, 1913 2,523,088 Goddard Sept. 19, 1950 2,570,591 Price Oct. 9, 1951 2,575,677 Neu Nov. 20, 1951 2,585,626 Chilton Feb. 12, 1952 2,610,464 Knoll Sept. 16, 1952 2,611,239 Briggs Sept. 23, 1952 2,640,316 Neal June 2, 1953 FOREIGN PATENTS 255,484 Germany Feb. 8, 1912 

